Page 85 - Clinical Manual of Small Animal Endosurgery

Operative Arthroscopy 73

trocar directly along the path of the triangulation needle. The triangula-
tion needle is removed and an instrument cannula is slipped over the
trocar and into the articular space.
Arthroscopic investigation of dogs affected with elbow disease has
contributed considerably to our current understanding of the lesions
traditionally grouped together as ‘elbow dysplasia’. The magnified view
achieved arthroscopically has led to the recognition that lesions that were
historically considered as isolated conditions often occur concurrently.
This is especially true for lesions of the medial aspect of the humeral
condyle and of the ulnar coronoid process and hence the term medial
compartment disease has become popular to describe this common
manifestation of elbow dysplasia. While in most clinical cases affected
with either medial humeral condylar disease or ulnar coronoid disease
it is probable that there is a degree of pathology in both areas, for the
sake of clarity the following discussion will deal with each condition
separately.

Arthroscopically assisted surgery of medial coronoid lesions of the ulna
A variety of appearances of the medial coronoid process of the ulna
characterise different manifestations of its disease. The mildest arthro-
scopic appearance of disease shows softening of the articular cartilage
while at the other end of the scale there may be eburnation of cartilage
exposing subchondral bone, often with a completely separated fragment
from the coronoid process (Fig. 3.9). When the arthroscopic changes
appear mild, a blunt probe is used to palpate the surface of the coronoid
process. The cartilage may appear softened, or there may be the impres-
sion of a linear indentation in the cartilage crossing the coronoid process
due to a fissure line in the subchondral bone beneath. Firm pressure

Fig. 3.9 Right elbow. Fragmentation of the ulnar coronoid process. The
medial aspect of the radial head is visible in the background.